Read the following SAT test question and then click on a button to select your answer.

In an 8-gram solution of water and alcohol, the ratio by mass of water to alcohol is 3 to 1. If 12 grams of a solution consisting of 2 grams water for each gram of alcohol is added to the 8-gram solution, what fraction by mass of the new solution is alcohol?

(A) 1/6
(B) 3/10
(C) 5/12
(D) 7/12
(E) 5/24

来源:可可英语 http://www.kekenet.com/sat/201407/313136.shtml